Re: [boost] [type_erasure]any(const binding<Concept>&, ...) compile error

Subject: Re: [boost] [type_erasure]any(const binding<Concept>&, ...) compile error
From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2012-07-27 14:08:53

AMDG

On 07/27/2012 09:49 AM, Larry Evans wrote:
> 
> The attached, when compiled with:
> 
>       #define CONSTRUCTIBLE_PH
> 
> fails compilation despite satisfying this Concept constraint
> mentioned above.
> 

It doesn't satisfy the requirements.

> However, when:
> 
>      //#define CONSTRUCTIBLE_PH
> 
> it compiles & runs OK.  The compiling version just doesn't use a
> placeholder in the args to Sig of constructible.
> 
> Why doesn't the one with the placeholder in the Sig args compile?
> Maybe I'm not understanding what's meant by:
> 
>   Concept must contain a matching instance of constructible.
> 
> Could you please explain what I'm missing?
> 

You're passing an argument of type ph_value<_a>.
How would constructible<_a(const _a&)> (which
is the copy constructor) be viable?

In Christ,
Steven Watanabe